This invention relates generally to refrigerator controls and more particularly to an improved circuit for efficiently controlling the temperatures in the refrigerator compartments.
Household refrigerators typically comprise a freezer compartment and a fresh food compartment separated by a partition. The freezer compartment is cooled by a fan circulating air over an evaporator situated in the freezer compartment. The fresh food compartment is cooled by diverting chilled air from the freezer compartment to the fresh food compartment through an air passage in the partition wall. The temperatures in the compartments gradually rise due to heat transfer through the walls and doors of the refrigerator as well as from door openings and the loading of food items therein. Various methods for controlling the temperatures of the freezer and fresh food compartments are known, but these known methods typically cause the evaporator fan to be operated whenever either compartment requires cooling. This results in frequent operation of the evaporator fan with a corresponding expenditure of energy.
Accordingly, there is a need for an arrangement for obtaining adequate temperature stability within both food compartments of a refrigerator with minimum energy consumption.